Air becomes liquid at about minus 190 degrees Celsius.
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
The sky is blue because when sunlight collides with our atmosphere, colours of the shortest wavelengths (violet and blue) are scattered - and our eyes are more sensitive to see blue.
Dominica, Mexico, Zambia, Kiribati, Fiji and Egypt all have birds on their flags.
Most gemstones contain several elements, except diamond which is all carbon.
When snakes are born with two heads, they fight each other for food.
The most remote island in the world is Tristan da Cunha, which is above the sub-Antarctic zone.
The DNA in a single human cell is 37 metres long when unravelled.
The world seahorse population has dropped 70% in the past 10 years.
Every minute, 30-40,000 dead skin cells fall from your body.